Buns eating lavender plants

I have quite a bit of lavender in my garden which the buns like to eat. I have started cutting a sprig off and putting it in their runs. Is lavener OK for them and how much should they be allowed to eat?

I thought it was OK for them as mine often raid the plants but until the other day I have never pulled sprigs off and put it in their runs (so I've never actively encouraged them to eat it) but will do from now on.